1. Field of the Technology
The present disclosure relates generally to mobile communication devices which communicate with wireless communication networks such as wireless local area networks (WLANs), and more particularly to improved scanning methods and apparatus of a radio frequency (RF) band for WLANs in an unknown regulatory domain.
2. Description of the Related Art
In wireless communication networks, such as wireless local area networks (WLANs) which operate in accordance with 802.11-based standards, a mobile communication device scans radio frequency (RF) channels of an RF band to identify information about the local WLANs. Scanning may be performed in either a passive scan mode or an active scan mode. The passive scan mode utilizes a wireless receiver of the mobile device to monitor RF channels for a beacon frame from any wireless APs of the WLAN. On the other hand, the active scan mode utilizes a wireless transmitter of the mobile device to transmit a probe request and the wireless receiver to monitor the RF channel for any probe responses from wireless APs of the WLAN.
In each country or region of mobile device operation, the use of RF bands are regulated and defined by regulatory bodies of the country or region (e.g. the FCC in the US and Canada). However, the mobile device may be operating for the first time in one of several different countries or regions where regulatory domain information for the RF band is unknown. When regulatory domain information is unknown, the passive scan mode of the mobile device is required as some RF channels are reserved for non-WLAN operations in certain regions. When regulatory domain information for a region is known, active scan modes of the mobile device are allowed as defined by the domain. Use of a passive scan operation is less efficient than an active scan operation while waiting to obtain such regulatory domain information. As apparent, regular use of the passive scan operation significantly increases battery power consumption of the mobile device while the regulatory domain information is unknown.
Accordingly, what are needed are methods and apparatus for efficient scanning of RF bands in unknown regulatory domains for mobile devices operative in WLANs.